Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Peanut worms are annelids

03.03.2011
The phylum Annelida has just gained a new member / Peanut worm is no longer recognized as separate group

Recent molecular phylogenetic analysis has shown that the marine animals known as peanut worms are not a separate phylum, but are definitely part of the family of annelids, also known as segmented worms. This is a classification that seemed questionable in the past in view of the fact that peanut worms – or the Sipunculidae, to give them their scientific name – have neither segments nor bristles.


Sipunculus nudus of the group of Sipunculidae with a length of about 8 centimeters. photo/©: Dr Anja Schulze, Texas A&M University at Galveston, USA

The latter are considered typical characteristics of annelids, which include more than 16,500 identified species and to which our common earthworm belongs. "Our molecular data clearly demonstrates that there is no doubt anymore that the Sipunculidae should be classified as members of these segmented worms," explains Dr Bernhard Lieb of the Institute of Zoology at Johannes Gutenberg University Mainz (JGU). The results were obtained as part of a broad study in which the phylogenetic development and relationships within the phylum Annelida were analyzed in terms of basic molecular biology to be then re-evaluated. Participating in the project are the universities of Osnabrück, Potsdam, Mainz, and Leipzig, together with the Max Planck Institute of Molecular Genetics in Berlin. The results have now been published online in the journal Nature.

"The relationships between the various annelids with regard to both morphological and molecular biological aspects have been a matter of dispute," states Lieb. Segmented worms are the most prevalent of marine macrofauna – their habitat ranges from tidal zones to the deep oceans. Usually, they have been divided into two main classes: the Clitellata, which have few bristles, e.g. earthworms, and leeches on the one hand and the Polychaeta, literally the 'many bristled', on the other hand. The evolutionary and deep branching patterns of annelid lineage are still the subject of on-going scientific debate, although it has become increasingly clear that other groups that had previously been classified separately, such as peanut worms and beard worms, are actually members of this phylum. By means of identifying some 48,000 amino acid positions in 34 different representatives of the phylum Annelida, the research group headed by the universities of Osnabrück and Potsdam has put together the hitherto most detailed database for the family of segmented worms. This has enabled the group to re-evaluate and reconstruct the phylogenetic interrelationships and evolution of this extensive and highly diverse group of animals.

The molecular data on Sipunculus nudus – the peanut worm – gathered by the team in Mainz led by Bernhard Lieb shows that the genetic characteristics of the worm, which lives in sand and silt at the bottom of the sea, clearly indicates that it is a member of the annelid family. In evolutionary terms the peanut worm is likely to be a basal group that diverged very early during evolution. It is conjectured on the basis of the sparse fossil record that the annelids first appeared in the Cambrian Period, roughly 550-490 million years ago. "We assume that segmentation was a very early characteristic of the annelids and that the peanut worm has lost its segmentation during the course of evolution," clarifies Lieb.

Primarily, new DNA sequencing technologies, so-called next-generation sequencing (NGS), made such comprehensive genetic investigations become possible. The Illumina Hiseq2000 sequencer recently acquired by the Institute of Genetics at JGU can analyze vast amounts of data, and sequence up to 200 gigabases of DNA per run within a single week. This means that whole genomes can be sequenced in a relatively short time, opening up completely new avenues for wide-ranging research.

Petra Giegerich | idw
Further information:
http://www.uni-mainz.de/eng/14040.php
http://www.staff.uni-mainz.de/lieb/

Further reports about: Annelida DNA Genetics Peanut Sipunculidae deep ocean molecular data segmented worms

More articles from Life Sciences:

nachricht Hidden dynamics detected in neuronal networks
23.07.2019 | Forschungszentrum Juelich

nachricht Towards a light driven molecular assembler
23.07.2019 | Christian-Albrechts-Universität zu Kiel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: MOF@SAW: Nanoquakes and molecular sponges for weighing and separating tiny masses

Augsburg chemists and physicists report how they have succeeded in the extremely difficult separation of hydrogen and deuterium in a gas mixture.

Thanks to the Surface Acoustic Wave (SAW) technology developed here and already widely used, the University of Augsburg is internationally recognized as the...

Im Focus: Better thermal conductivity by adjusting the arrangement of atoms

Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.

In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...

Im Focus: First-ever visualizations of electrical gating effects on electronic structure

Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.

Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...

Im Focus: Megakaryocytes act as „bouncers“ restraining cell migration in the bone marrow

Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.

Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...

Im Focus: Artificial neural network resolves puzzles from condensed matter physics: Which is the perfect quantum theory?

For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.

Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

Hidden dynamics detected in neuronal networks

23.07.2019 | Life Sciences

Towards a light driven molecular assembler

23.07.2019 | Life Sciences

A torque on conventional magnetic wisdom

23.07.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>